Power-actuated brake mechanism for automotive vehicles



Dec. 31, 1929.

c. s. BRAGG E1' AL POWER ACTUATED BRAKE MECHANISM FOR AUTOMOTIVE.VEHICLES Filed April 21, 1927 ..7/14 IZZ INVENTOR ATTORNEY Patented Dec.31, 1-929` UNITED ysrarase?`lfrlfeNr [o1-*FICE ,CALEB s. ERAGG, OEParnuk BEACH, FLORIDA, ANDVICTOR W, xLIEsRATm-OE :PORT WASHINGTON, NEWVYORK, assIGNoRs To BRAGG-:KLIESRATH CORPORATION, T'

ILONG ISLAND CITYNE-w YORK, A CORPORATION O E N Ewxonx rowER-ACTUATEDBRAKE ianoHaNIsrfrron AUTOMOTIVE VEHICLES Application ledApril 21,\1927.SeraVNO. 185,469.

Ourinvention consists the novel features hereinafter described,reference being had to the accompanying drawing which` shows anembodiment of our invention select- 5 ed by us for purposes ofillustration, and the said invention is fully lowingdescription andclaims.

n`Our invention relates-to power actuated brake mechanism for automotiveVvehicles propelled by an inteinal combustion engine, having a suctionpassage for supplying the normal explosive charges to the engine` cylin-I ders, and having an air inlet aperture for the admission ofatmospheric air which forms the larger part of such explosive charges,and; in which the rarefaction within the suction passagel upon which theoperation of a suction 'actuated power vactuator connected with thebrake mechanism of the vehicle depends, is

rendered effective by shuttingoif to a greater or less extent theadmission of atmospheric air to the suction passage of the engine, as bysuction passage, and the carburetorwhich iujects liquid fuel into thestream of atmospheric air drawn into said passage. The carburetorordmarily comprlsesa fuel chamloer or reservoir provided with means,usually a float and float valve operated thereby for maintaining apredetermined liquid level of the liquid fuel in said chamber, whichis'ordinarily termed the float chamber, said float chamber beingconnected with a jet or nozzle located within a vertical portion -of thesuction passage, and 'dlschargmg vertically v thereinto at a-pointapproximately on a horizontal line with the predetermined liquid levelin the reservoir or float chamber, the said suction passage beingordinarily slightly narrowed in diameter adjacent to the dischargeaperture of the jet or nozzle, to form whatis ordinarily termed aVenturi tube or passage. vIn the case of ordinary carburetors, the spacein the fuel chamber or float chamber above the liquid level isordinarily.

in communication with theatmosphere by a suitable vent opening oropenings, and when the engine" is not in operation the liquid in the jetwill be subject also to atmospheric pressure within the Venturi passage,thus disclosed in the foltermed loading up. the

equalizing pressures at the discharge aperture of thej et and onthesurface ofthe liquid in the float chamber, which prevents the` fuelfrom being discharged from the jet and wasted. When the-engine is inoperation and 'term herein the normal rarefaction. This reduction'ofpressure will increase somewhat with the opening of the throttle'andvaria'- tion in the speed of the engine, which enables the atmospheric4pressure on the surface of the liquid fuel in the reservoir to force orinject, or otherwise discharge portions of the liquid fuel into thecurrent of atmospheric air, to produce the explosive mixtureconstituting the explosive charges for the engine.

4VVhere'me'ans are provided vfor Operating a a valve located between theair inlet'to the ated'device is connected to the suction passage'between such shut-off valve and the carburetor,the closing of this airinlet aperture more or less and the consequent creation of a supernormaldegree of rarefaction in the Venturi passage, will cause lthe fuel inthe reservoir float chamber of the carburetor to be expelled into'thesuction passage far in excess of the normal proportion of fuel in theexplosive mixture ldesired and normally furnished to the engine, andfurthermore in excess of:

the quantities which can bevaporized by the restricted quantities of airpassing through the closed or partially closed shut-off valve, and theresult will be the enrichment of the mixture to such'an extent that itwill not readily explode, and Imay eventually cause the engine to stall.This is ordinarily engine.

l The object of our preent invention is to overcome this difficulty, and.to this end we provide an equalizing passage between the carburetorioat chamber above the liquid level therein and the rtion of the Venturipassage adjacent to t e discharge aperture of the fuel nozzle therein,and automatic valve mechanismfor controlling said equalizing passage andthe air inlet or vent aperture or passage for the float chamber, saidautomatic valve mechanism being constructed to normally maintain thesaid equalizing passage closed and the air inlet or vent passage open,and to be operated by a supernormal rarefaction within the portion ofthe Venturi passage to which the equalizing passage is connected, toshift said va ve mechanism into position to open the equalizing passageand close the vent passage of the float chamber. It follows from thisconstruction that when the air inlet aperture is closed to a greater orless extent for the purpose of producing an operation of the suctionactuated device, this valve mechanism will be automatically actuated bythe supernormal rarefaction produced in the Venturi passa e, and willimmediately equalize pressures etween the surface of the liquid in thefloat chamber and the surface of the liquid in the nozzle adjacent toits discharge aperture, thus preventing the loading up of the engine inthe manner described, and preventing the stalling of the engine upon theoperation of which the rarefaction for effecting the operation of thesuction actuated device depends, and also reventin the presence ofexcess unvaporize liquid uel in thesuction passage which might find itsway into the suction actuated device and injure the packings and gasketsthereof.

In the accompanying drawing which illustrates one embodiment of ourinvention selected by us for purposes of illustration- Fig. 1 is adiagrammatic vview illustrating an installation in an automotive vehicleprovided with an internal combustion en ine for propelleing the vehicle,and brake mec anism, of a suction actuated power actuator operativelyconnected with the brake mechanism and the suction passage of theengine', between the throttle valve and the air intake, and operativemeans for closing more or less the air inlet to the suction passage andembodying our presentinvention, the actuator being illustrated insection. l

Fi 2 is a detail sectional elevation drawn to a arger scale and showingthe carburetor, the adjacent portions of the suction passage, andrelated parts illustrated in Fig. 1.

Fic. 3 is a detail sectional view of the valve chamhber showing a slightmodification.

Referring to this drawing, it is to be understood Ithat Fig. 1represents more or less diagrammatically an installation of poweractuated brake mechanism of the kind previously referred to in` anautomotive vehicle provided with an' internal combustion engine. Theentire engine is not shown,'bu t is indicated in part by the intakemanifold, 1, provided with a vertically disposed tubular portion, 2,constituting with the manifold the suction passageof the engine, thetubular portion, 2, being provided at its lower end with an inlet, 3,for atmospheric air to be mixed with liquid fuel above the carburetornozzle and form the explosive mixture, or in other words the explosivecharges for the engine cylinders. 4 represents the liquid fuel reservoiror float chamber of the carburetor, which is provided with a fuel supplypipe, 5, controlled by a. needle valve, 6, which is in turn controlledin this instance by a float, 7 and float actuated levers, 8, operativelyconnected with the stem of the needle valve, and pivotally supported inthe usual manner for the purpose of maintaining a predetermined liquidlevel within the float chamber. Any suitable means may be employed forthis purpose, and the particular means shown forms no part of ourpresent invention. The carburetor float chamber is provided with a fuelpipe or tubular passage, 9, extending into the portion, 2, of thesuction passage of the engine, below the throttle valve, where it isprovided with a vertically disposed nozzle, 10, having a' dischargeaperture, 11, at its upper enrl, the portion of the vertical pipe orpassage, 2, being preferably reduced in diameter adjacent to the saiddischarge aperture, as by a sleeve, 12, to form the Venturi passage, 13,to surround the nozzle in the usual manner. The liquid fuel reservoir orfloat chamber, 4, as shown in Fig. 2, is in this instance provided witha valve chamber, 14, secured to the top plate, 4*, of the oat chamber,and provided with an air inlet valve chamber, 15, and an equalizingvalve chamber, 16, provided with valve seats, 17 and 18, respectively,at opposite ends of a connecting passage, indicated at 19. Thisconnecting passage is in communication, by a vertical passage, 20, withthe float chamber above the liquid level therein, so that the floatchamber may be placed in communication with either of the valvechambers, 15 or 16. 'lhe float chamber is otherwise air tight. The saidvalve seats are adapted to be engaged by an air inlet valve, 21, and anequalizing valve, 22, respectivel which are oppositely disposed, and reerably connected in such manner that w en one of said valves is seated,the other will be held open.

For convenience of assembling, the air inlet valve, 21, is provided witha valve stem, 23, rigidly secured thereto, extending through theaperture, 19, and provided with a reduced portion, 24, extending throughthe equalizing valve, 22, thus forming a shoulder, and separating orspacing the valves the required distance apart. The reduced portion ofthe valve stem is provided with a securing nut,

25, for holding the equalizing-valve rigidly with respect to the stein,the stem being further reduced in diameter` to form asinooth bearing toguide the valves. The equalizing valve chamber, 16, is closed at itsouter end by a cap, 26, containing a partition, 27, provided with anapertui'e to receive the outer end of the valve' stein, and a spiralspring. 2S. surrounding the valve stein is interposed between thepartition, 27, and the equaliz/iing -valve, 22, holding the equalizingvalve. closed, and the air inlet valve, 21, open, as clearly shown inFig. 2. The cap, :'26, is provided wit-l1 a tubular outlet. 29,com-municating with the equalizing valve chamber, 16, by suitableapertures in the partition, 27, one of the which is shown, at 30. andsaid tubular outlet is connected by an equalizing pipe, 31, with thepart, 2, of the suction passage between the throttle valve andthe airinlet, and preferably adjacent to and slightly above the dischargeaperture, 11, of the carburetor jet or nozzle. The air inlet valvechamber, 15', is in communication with the atmosphere at all times. vInthis instance we have shown said chamber provided with a cap, 232,having a vent aperture, or passage, 83, therein. The spring, 28, isnormally calibrated so that it will hold the valves in the positionsindicated in Fig. 2, n'iaintaining a direct communication between thefloat chamber and the atn1osphere,and closing communication between thefioat chamber and equalizing passage at all times, except when thesuction actuated device, hereinafter described, is operated.

In Fig. 1 we have represented diagrammatically at B, the brake mechanismof the vehicle, which may be of any desired type and may be applied totwo or more wheels, as desired. In this instance, I), representsdiagrammatically a lever, by means of which the brakes, B, may beapplied, and s, represents diagraininatically the yielding retractingmeans or springs for returning the brake mechanism to normal position. Prepresents a suction actuated power actuator comprising in this instancea cylinder, 34, open to the atmosphere at one end, as indicated at 35,and provided with a piston, 3G, the piston rod, 37, of which is shownconnected by linkage, in-

dicated at 38, with the brake mechanism, as

the brake operating lever, b. vThe forward end of the .actuator cylinderis shown connected by a pipe, 39, with the portion, 2, of the suctionpassage of the engine between the air inlet, 3, and the throttle valvefor the engine. The pipe, 39, could be connected with the suctionpassage between the carburetor and thel throttle valve, but in such casethe air withdrawn from the actuator when the latter is operated, wouldnot receive Afuel from the jet and would tend to stall the engine. Weprefer to connect the pipe, 39, between the air inlet or intake, 3, andthe carburetor, as

shown, 'so that the air from the carburetor will be earbureted and willnot materially interfere with the operation of the engine, vo1' stall itif idling. 7e have also shown the tubular portion, 2, of the suctionpassage between the point of connection of the pipe, 39, therewith, andthe air inlet, 3 with a valve of the butterfly type, indicategd at 40,pivotally mounted therein, and provided with an actuating arm, 41, inthis instance, connected by a link, 42, with a pedal, 43, pivoted to astationary part of ,the vehicle at 44, and provided with a pedal, 45,and retracting spring, 46. Suitable stops are preferably provided foi'limiting the forward movement'of the foot lever in adirection to closethe valve, 40, to provide suficientair to keep the engine running idle,whichis preferably 'an adjustable stop, and maybe applied either to thefootlever itself or. the valve operating arm, 41. In this instance, wehave shown a set screw, 47, for engaging the arm, 41, to limit theclosing movement of the valve, 40, and we have also shown an adjustablestop, indicated at 48, and in this instance arranged to engage the footlever, 43, to limit the return movemen-t of the foot lever, so as tohold the valve, 40, normally in wide open position.

'In Fig. 1 the footlever is shown in its lowest posit-ion, the valve,40, in closed position, and the power actuator piston at the -end of itspower stroke, the brake mechanism being fully applied.A It will be seenthat the closing of the valve, 40, to a greater or less extent,correspondingly shuts off the admission of atmospheric airto the tubularportion 2, of the suction passage, and when the engine is in opeiation,the suction of the' engine cylinders will necessarily produce asupernormal degree of rarefaction at the discharge aperture of the jetwithin the suction passage between the valve, 40, and the enginecylinders. The reduction of pressure in the said passage will beinstantly felt in the equalizing passage, 3l, and valve chamber, 16,opening the equalzing valve, 22, and simultane` ously closing the airinlet valve, 21, thus equalizing pressures on vthe surface of the v fuelin the ioat'chainber, and in the suction passage above the nozzle, 10,and preventing the discharge of fuel by unequal pressures on the fuelWithin the .float chamber and jet other than the normal rarefactioncaused by the Venturi tube,.and permitting the. carburetor to functionin the ordinary manner during the operation of the Vpower actuator. Whenthel brake mechanism is fully applied, there will be a reduction ofpressure in the float chamber upon the surface of the fluid and the topof the iioat, which will be equivalent tovan increase of pressure in thefuel supply pipe. vIt will, therefore, require greater pressure to closethe fuel inlet needle valve, and a correspondingly greater submerging ofthe float. Hence under these conditions there will be a slight rise ofthe liquid level in the float chamber, and the discharge aperture of thejet will be so located that this rise of liquid level in the iioatchamber will insure the'discharge from the jet of suilicient fuel tocarburet the air passing through the Venturi tube under suchconditions,iso that the engine will not stall if idling. It Will be seenthat the degree of supernormal rarefaction' within the suction passagemay be varied by moving the valve, 40, to a greater or less degreetoward its closed position, and the operator may, therefore, control thedegree of pressure exerted on the brake mechanism by the power actuator,by means of the foot lever, 43, the valve,

40, acting very much like the ordinary choke valve with which internalcombustion engines are usually provided, to shut off more or less theadmission of atmospheric air to'the enne When the pedal lever, 43, isreleased gy the operator, it will be returned to its normal position bythe retracting spring, 46, and the valve, 40, will be wide open,restoring atmospheric pressure within the portion, 2, of the suctionpassage, and closing the equalizing valve and opening atmospheric valveand connecting the top of the float chamber with the atmosphere. Thepressures on opposite faces of the piston, 36, of the power actuator, P,will be equalized, and the brakes will be immediately released, thebrake mechanism and piston, 36, being returned to normal position by theretracting means, as springs, a, Our invention, therefore, presents avery simple construction in which the ower actuator can be operated tothe desire extent b simply placing the foot on the pedal, 45, andepressing the foot lever, 43, to apply the brakes without danger ofloading up the engine or stalling it, and the brakes may be instantlyreleased by relieving the pressure of the foot on the pedal, 45, orremoving the foot therefrom. It will be understood that suitable meansare provided, indefpendent of the pedal lever, 43, and valve, 40,

or controlling the speed of the engine.v

We have illustrated, at, 50, the usual throttle valve for controllingthe speed of the engine, which is operatively connected with theusualhand lever and foot accelerator, not shown, in any usual or desiredmanner, or which may be operated in any other desired way.

It will be understood that the equalizing passage and controlling valvemechanism herein described in connection with the carburetor and suctionpassage will be operated in preventing the loading up of the engine,when from any cause an abnormal degree of rarefaction exists in thesuction passage, for example, when the ordinary choke valve whichoperates substantially like the valve, 40, to partially shut 0H theadmission of air to the suction passage and carburetor to produce aricher mixture, as in starting the engine, is closed. In such case theequalizing passage and valve mechanism, as described, may be employed toprevent the abuse of the choke valve and the consequent loading up ofthe engine. It will also be understood that if the vent passage, 33, ismade sufficiently minute so that even if open it will not prevent theequalization of pressures on the liquid in the float chamber' anddischarge aperture of the nozzle, when the equalizing valve is opened,the vent valve may be dispensed with and the device would be entirelyoperative. We prefer, however, to provide the vent valve for closing thevent passage when the equalizing valve is opened, as shown and describedherein.

Ve do not wish to be limited to a construction in which the automaticopening of the equalizing valve is accom anied by the closing of thevent for the car uretor fioat chamber. We have found that if asufficiently minute vent aperture is provided for the iioat chamber, thedevice is operative without closing the vent aperture. In Fig. 3 wehave/illustrated a slight modification of the valve chamber, in whichcorresponding parts are given the same reference characters as in Figs.1 and 2, with 100 added, to avoidv repetition. In this gure the valvechamber, 114, connected with the suction passage in the same manner aspreviously described, and is provided with an equalizing valve, 122,held normally closed by the spring 128. The float chamber is providedwith a very minute vent aperture, indicated at 133, which as hereinshown, is formed in the ca 132, closing the outer end of the valve chamer, but it may be located wherever desired. This vent opening is alwaysin communication with the atmosphere and with the fioat chamber abovethe liquid level therein, but is of such small diameter that when theequalizing valve is opened by the reduction of pressure in the suctionpassage, as previously described, the pressure upon the liquid in theiioat chamber will be equalized with that in the suction passage and thevery small amount of air admitted through the vent aperture will notafect the operation of the device, and a rarefaction will be producedabove the liquid in the iioat chamber, substantially equal to that inthe suction passage at the jet nozzle.

What we claim and desire to secure by Letters Patent is 1. Thecombination with an internal combustion engine provided with a suctionpassage or supplying the explosive mixture to the cylinders having anair inlet for supplying air for the explosive mixture, and a shutoffvalve for said air inlet, ofa carburetor provided with a liquid fuelchamber, means for normally maintaining a predetermined liquid leveltherein, and a jet nozzle discharging within the suction passage, saidfuel chamber being provided above the liquid level structed toautomatically open said equal` izing passage when said shut-off valve issuffieientl-v lclosed While the engine is running toproducc a degree ofrarefaetion at the jet nozzle.

2. The combination with an internal combustionngine provided with asuction passage for supplying the explosive mixture to the cylindershaving an air inlet for supplyingair for the explosive mixture, and ashutofir valve for said air inlet, of a carburetorl provi-ded with aliquid fuel chamber, means for normally maintaining a predeterminedliquid level therein, and a jet nozzle discharging within the suctionpassage, said fuel chamber being provided above the liquid level thereinwith a vent passage for normally connecting it with the atmosphere, andan equalizing passage for connecting it with the suetion passageadjacent to the jet nozzle, and' means for normally closing saidequalizing passage and opening said ventl passage, constructed toautomaticallyopen said equalizing passage and close said vent passagewhen said shut-olf valve is sufliciently closed while v the engine isrunning to produce a degree of rarefaction at the jet nozzle.

3. The combination with an internal combustion engine provided with avsuction passage for supplyingtlie explosive mixture to the cylindershaving an air inlet-for supplying air for the explosive mixture, andashutoifv valve for said air inlet, of a carburetor provided with aliquid fuel chamber, mean-s for normallymai'ntaining a predeterminedliquid level therein, and a jet nozzle discharging with-in the lsuctionpassage, said fuel chamber being provided above the liquid level thereinwith a vent passage for normally connecting it with the atmosphere, andan equalizing passage for connecting` it with the suction passageadjacent to the jet nozzle, -a.

valve for controlling the said'equalizing pas-y sage, and yielding meansfor normally holding the said equalizing valve in closed position, andconstructed to yield and permit the automatic opening of said equalizingvalve when the degree of rarefaction in the suction passage exceeds thatnormally existing when the engine is running and the shut-oli' v'alve-is fully open, to prevent the discharge of fuel from said nozzle inexcess of the quantities which can Vbe vaporized by the restrictedquantities of air admitted tothe suction passage and to prevent theaccumulation of unvaporized liquid fuel in the suction passage.

4. The combination with .an internal combustion engine provided with asuction pas- 5 sage for supplying the explosive mixture to thecylindersI having an air inlet for sup lying air for the ex )lesivemixture, and a s utoff valve for sai air inlet, ofa carburetor providedwith a liquid fuel chamber, means for normally maintaining` apredetermined liquid level therein, and a jet nozzle discharging withinthe suction passage, said fuel chamber being provided above the liquidlevel therein with a. vent passage for normally connecting it with theatmosphere, and an equalizing passage for connecting it with the suctionpassage adjacent to the jet nozzle, a

valve for controlling the said equalizing passage, and yielding meansfor normally holding the said equalizing valve in closed position, andconstructed to yield and permit the automatic opening of said'equalizing valve when the degree of rarefaction in the suction passageexceeds that normally 'existin when the engine is running and the shut-ovalve is fully open, a normally open vent valve for said 'vent passage,and operative connections .between said valves whereby the said ventvalve will be normally held open by said yielding device, andautomatically closed by the movement of the equalizing valve to openposition.

5. The combination with an internal combustion engine, provided with asuction passage for supplying explosive mixture to thev cylinders havingan inlet aperture for supplying air for the explosive mixture, and ashut-olf valve for. said air inlet, of a carburetorprovided with a floatchamber, a liquid fuel supply under approximately yconstant pressure, aloat and float valve for maintaining normally a predetermined liquidlevel in said chamber, and a jet nozzle discharging within the suctionpassage and having its discharge aperture located substantially inhorizontal alignment with said liquid level, said float chamber beingprovided above the liquid level therein with `a normally open ventpassage communicating with the atmosphere, and an equalizing passagecommunieating with the suction passage 'adjacent to the jet nozzle, avalve ineehanisnri for normally controlling the equalizing passage andvent passage, and yielding means for normally holding said valvemechanism in posi- /tion to render said equalizing passage inoperative,and vent passage operative, whereby, when said shut-off valve is closedwhile the enginelis running, suiiciently to increase the degree ofrarefaction in the suction passage adjacent to the nozzle, said valvemechanism will close said vent and open said equalizing passage, 'sothat the pressures o'n the liquid fuel in the float chamber and in thedischarge aperture of the nozzle will be equalzed, and a degree ofrarefaction will be vproduced above the liquid in said float chamber,thereby insuring the discharge of only sufficient fuel Vfrom the jet tofuelize' the restricted quantity of air admted to the suction passa e.

li. The combination with an internal combustion engine provided with asuction passage having an air inlet aperture to supply the air for theexplosive charges, means located adjacent to said air inlet aperture forshutting oifvthe admission of air therethrough to the suction assagc, acarburetor provided o with a liquid ucl chamber, means for maintaining apredetermined liquid level therein, and a fuel jet nozzle located in thesuction passage between said air shut-oil means and the enginecylinders, a throttle valve located in said suction passage between saidjet nozzle and the engine c linders, said ioat chamber beingprovided a)ovetheliquidleveltherein with a vent aperture communicating with theatmosphere, 'and an equalizing passage, zo forv connecting it with thesuction passage j adjacent to the jet nozzle, cont-rolling valvemechanism for said passages normally mamtaining the equalizing passageclosed and the vent passage open and operable when the said shut-offmeans is moved in a direction toward closed position sutliciently toproduce a degree of rarefaction at the jet when the e n gine is runningto automatically open said equalizing passage -and close the said ventpassage, a suction actuated device, operatlvely connected with thesuction passage between said throttle valve and said shut-off valve, andcontrolled by said shut-oft' valve, whereby when said shut-off valve isoperated in a direction to close the air inlet and effect the operationof the suction actuated device, said valve mechanism will beautomatically operated to equalize the pressures above the fuel in thefloat chamber and jet nozzle of said carburetor to prevent the dischargeof fuel by atmospheric pressure in the fuel chamber in excess of thequantities which can be Vaporized by the restricted quantities of airadmitted, and to prevent the accumulation of unvaporized liquid fuel insaid suction passa e and in said suction actuated device.

7. 'he combination with an internal combustion engine provided with asuction passage having on air inlet aperture to supply the air for theexplosive charges, means located adjacent to said air inlet aperture forshutting off the admission of air therethrough to the suction passage, acarburetor provided with a liquid fuel chamber, means for maintaining apredetermined liquid level therein, and a fuel jet nozzle located inthesuction passage between said air shut-oil' means and the enginecylinders, a throttle valve located in said suction passage between saidjet nozzle and the engine cylinders, said float chamber being providedabove the liquid level therein with a vent aperture communieating withthe atmosphere, and an equalizing passage for connecting it with thesuction passage adjacent to the jet nozzle, a vent said suction passagebetween the throttle valve and the shut off valve, and controlled by theshut-off valve, whereby when the shut-off is operated in a direction toclose the air inlet and effect the operation of the suction actuateddevice, the said valves will'be automati- `-eally operated to close theventpvalve and open the equalizing valve.

8; The combination with an internal combustion engine provided with asuction passage haviug-an air inlet aperture to supply the air for theexplosive charges, means located adjacent to said air inlet aperture forshutting off the admission of air therethroughto the suction passage, acarburetor provided with a liquid fuel chamber, means for maintaining apredetermined liquid level therein, and a fuel jet 'nozzle located inthe suction passage 'between said air shut-off means and the enginecylinders, a throttle valve located in said suction passage between saidjet nozzle and the engine cylinders, said float chamber being providedabove the liquid level therein with a vent aperture communicating withthe atmosphere, and an equalizing passage for connecting it with thesuction passage adjacent to the jet nozzle, valve mechanism includingoppositely disposed valves for said passages connected for jointoperation'to seat one of said valves and open the other by a movementthereof in either direction, a spring for holding said valves inopposition to close the equalizing passage and maintain the vent passageopen, said spring being calibrated to overcome any normal degree ofrarefaction in the suction passage When the engine is running and theshut-oif valve is open, a suction actuated devicel comprising a cylindercommunicating with the suction passage between said shut-oif valve andthe throttle valve, and a piston in said cylinder, means for holdingsaid shut-olf valve normally in open position, and an operator operatedpart connected with said valve, whereby when said shut off valve ismoved-toward closed position to effect the operation of the suctionactuated device, the increase in the degree of rarefaction produced inthe suction passage will automatically shift said valves to close thevent valve and open the equalizing valve, and eii'ect equalization ofpressures between the float chamber and the jet nozzle.

9. The combination with an internal combustion engine provided with asuction passage having an air inlet aperture to supply the air for theexplosive charges, means lo` cated adjacent to said air inlet aperturefor lloA buretor proidded with a liquid fuel chamber,l means formaintaining va predetermined liq\ uid level therein, and a fuel jetnozzle located Vin the suction passage between said air shutloil' meansand the engine cylinders, a throttlel valve located in said suction'passage betweensaid jet -nozzle and the engine cylinders, said floatchamber being provided .with a' valve casing provided with separatevalve cham-p bers, a connecting passage between said.v chamberscommunicatingwlth the floatA chamber above the liquid level therein, andoppositely disposed valve seats, o positely disposed valves in saidcasing, one o which is located in each chamber, a valve stem con'-necting said valves and holding them in such position that when one isseated the other is open, one of said valve chambers being incommunication with the atmosphere at all times by avent passage, and theother valve chamber being connected by an equalizing passage with thesuction passage adjacent to said nozzle, a spring normally holding saidvalves in position to maintain the valve controlling said equalizingpassage closed, and the valve controlling the vent passage open, asuction actuated device comprising a cylinder communicating at one endwith thev suction passage between said shut-off means and the throttlevalve, and a piston 1n said cylinder, an operator operated deviceconnected with said shut-oitl means, a retracting spr'ing therefor, anda stop for arresting the sluit-oil' means in open position, whereby whensaid shut-off means is moved toward closed position to elfect theoperation of the actuator, the increase in the degree of rarefactionwithin the suction passage will shift said oppositely disposed valves toclose communication between the float chamber and the atmosphere.

10. The combination with an internal combustion engine provided with asuction passage for supplying the explosive mixture to the lcylinders'having an air inlet for supplying air for the explosive mixture, and ashut-off valve for said air inlet, of a carburetor provided with aliquid fuel chamber, means for normally maintaining a predeterminedliquid level therein, and'avjet nozzle 'discharging 'within the suctionpassage, said fuel chamber being provided above the liquid level thereinwith an equalizing passage for connecting it with the suction passageadjacent to the jet nozzle, and-means for normally closing saidequalizing passage, constructed to automatically open said equalizingpassage when the said shut-olf Valve is sufficiently closed While theengine is running to produce a degree of rarefaction at the jet-nozzle.

11. The combination with an internal conibustion engine provided withasuction passage for supplying the explosive mixture to the cylindershaving an air inlet for supplying air for the explosive mixture, and asluitoff valve for said air inlet, of a carburetor pric vided with 'aliquid fuel chamber, means for normally maintaining a predeterminedliquid level therein, and a jet. nozzle discharging within the suctionpassage, said-fuel chamber being provided above the liquid level thereinwith an eqnalizingpassage for connecting itwith the suction passageadjacent to theg-jet nozzle, and :i1-normally closed valve for said"equalizing passage, eonstructedgto automatically open saidequalizing'pass'ag VVwhen said l' shut-olf valve is suliiciently closedwhile the engirie is running,toproduce a degree of vrarefaction at thejet nozzle. v 12. The combination with an internal coinbustion engineprovided with a suction passage for supplying the explosive mixture tothe cylinders having an air inlet for supplying air for the explosivemixture, and a shutoil' valve for said air inlet, of a 'carburetorprovided with a liquid fuel chamber, means for normally maintaining apredeterminedliquid level therein, and a Vjet nozzle discharging withinthe suction passage, said fuel chamber being provided above the liquidlevel therein with an equalizing passage for connecting it with thesuction passage adjacent to the jet nozzle, a .valve for closing saidequalizing passage, a spring holding said valve normally closed, andconstructed to automatically open' said equalizing passage when saidshut-off valve issuticiently closed while the engine is ruiming, toproduce a degree of rarefaction at the jet nozzle.

13. The combination with an internal combustionengine provided with asuction passage for supplying the explosive mixture to the cylindershaving an air inlet for supplying air for theexplosive mixture, and ashutoff valve for said air inlet, of a carburetor provided with a liquidfuel chamber, means for normally maintaining a predetermined liquidlevel therein, and a jet nozzle discharging within the suction passage,said fuel chamber being provided above the liquid level therein with`anequali'zing passage for connecting it with the suction passageadjacent to the jet nozzle, and a vent aperture of smaller crosssectional area than the equalizing passage, and a normally closed valvefor said equalizing passage constructed to automatically open saidequalizing passage when said shut-off valve is sufficiently closed whilethe engine is running to produce a degree of rarefaction atv the jetnozzle, and effecting approximately the saine degree of rarefaction atthe nozzle and within the float chamber.

14. In a brake system for automotive vchicles, the combination with aninternal combustion engine for propelling the vehicles, having a suctionpassage, an air inlet for supplying the air for the explosive mixture, a

trolling the admission of air through said air inlet, a throttle valvein said suction passage located between said air restricting valve andthe engine cylinders, and a carburetor for fuelizing said air, having afuel nozzle discharging into said suction passage between the said airrestrictng valve and the throttle valve, of a suction actuated device,provided with a movable pressure operated part operatively connectedwith brake mechanism, a tubular suction connection from said suctionactuated device connected with said suction passage between said airrestricting valve and said throttle valve, for establishingcolnmunication between the suction actuated device and the suctionpassage independently of the air inlet, and operator operated means forsaid valves, whereby the closing of said air restricting valve willel'ect the operation of the suction actuated device to apply the brakemechanism. Y

15, The combination with the suction passage of an internal combustionengine and a carburetor having its fuel jet arranged within the suctionpassage, of a suction operated power actuator and a discharge connectionfrom the power actuator to the suction passage which enters said suctionpassage on the side of the jet remote from the engine so that all airwithdrawn from the actuator will be carbureted.

16. The combination with the suction passage of an internal combustionengine and a carburetor having its fuel jet located in the suctionpassage, of a suction operated power actuator' and a suction connectionfrom said power actuator to the suction passage which enters saidsuction passage below the jet.

17. The combination with the suction passage of an internal combustionengine and a carburetor having its fuel jet located in the suctionpassage, of a suction operated power actuator and a suction connectionfrom said power actuator to the suction passage which enters saidsuction passage at a point to one side of said fuel jet furthest removedfrom the engine cylinders.

18. The combination with the suction passage of an internal combustionengine havingan air inlet, a carburetor having a fuel jet or dischargenozzle arranged in the suction passage and a throttle for controllingcarbureted air to said engine, of means for controlling the air enteringsaid air inlet, a

-suction operated power actuator, and a discharge connection from saidactuator to the suction passage between said controlling meansand thefuel jet.

19. The combination with lthe suction passage of an internal combustionengine having an air inlet and a throttle valve, of a carburetor havinga fuel jet located in the suction passage between the air inlet and thethrottle valve, a brake valve controlling the air entering said airinlet, and a suction operated power actuator connected to said suctionpassage at a point between the brake and throttle valves which insuresthe Carburation of air withdrawn from the actuator.

20. The combination with the suction passage of an internal combustionengine and a carburetor having a float chamber, and a discharge nozzlelocated Within the suction passage, of a power actuator, a suctionconnection from said actuator connected to the Suction passage at apoint so that air withdrawn from said actuator will be carbureted inpassing through the suction passage, means for regulating therarefaction in said suction passage, suction connection and actuator toop# erate the actuator, and means for automatically producing asubstantial equalization of pressures in the float chamber and suctionpassage adjacent the discharge nozzle.

21. The combination with the suction passage of an internal combustionengine and a carburetor having afloat chamber and a discharge nozzlewithin the suction passage, of a brake valve controlling the airadmitted to said suction passage, a suction operated power actuatorconnected to said suction passage at a point between the brake valve andthe discharge nozzle, said engine adapted to produce maximum rarefactionin the actuator to operate the same when said brake valve is closed,together with means for automatically producing a substantialequalization of pressure in the float chamber and suction passage aboutthe discharge nozzle.

22. The combination with the suction passage of an internal combustionengine and a carburetor having a fuel chamber, and a discharge nozzlelocated within the suction passage, of an equalizing passage connectingthe float chamber of the carburetor to the suction passage between theengine and the carburetor, al brake valve arranged on the opposite sideof the discharge nozzle from the equalizing passage and remote from theengine for controlling the air entering said suction passage, and meanswithin the equ alizin g passage acting to automatically open the samewhen a substantial rarefaction is produced in the suction passage by theclosure of the brake .valve and to automatically close the same, andvent the fuel chamber to the atmosphere when the brake valve is open.

In testimony whereof we affix our signatures.

CALEB S. BRAGG. VCTOR W. KLIESRATH.

